PROCEED AT YOUR OWN RISK. I TAKE NO RESPONSIBILITY IF THIS BREAKS YOUR GUN. Remove the inner barrel, fore-grip, and upper receiver (from the lower). Ideally you would secure the upper in a vise with the appropriate AR vise attachment. Then you apply heat to the barrel nut, apply the wrench and tap the handle of the wrench with a light hammer. The heat softens the glue and the tapping breaks the bond. The threads are clockwise like any jar in your house.